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Aftab H, Kemp M, Stensvold CR, Nielsen HV, Jakobsen MM, Porskrog A, Dessau RB. First molecular documented case of a rarely reported parasite: Plasmodium knowlesi infection in Denmark in a traveller returning from Malaysian Borneo. Travel Med Infect Dis 2023; 53:102580. [PMID: 37088361 DOI: 10.1016/j.tmaid.2023.102580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/03/2023] [Accepted: 04/19/2023] [Indexed: 04/25/2023]
Abstract
Plasmodium knowlesi has been reported as an emerging infection throughout the Southeast Asian region, especially in the Malaysian state of Sabah, where it accounts for the majority of the malaria cases reported. This is in contrast to Europe, where imported P. knowlesi is a rarely reported infection. We present a case of P. knowlesi infection in a Danish woman returning from a short trip to Malaysian Borneo. Microscopy of blood smears revealed 0.8% infected erythrocytes, but due to the atypical morphological presentation, a conclusive species identification was made by molecular methods. Plasmodium knowlesi is a potentially fatal infection and taking the increasing travel activity into consideration after the coronavirus disease 2019 (COVID-19) pandemic, P. knowlesi should be a differential diagnosis in patients with travel-associated illness returning from highly endemic Southeast Asian areas.
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Affiliation(s)
- Huma Aftab
- The Regional Department of Clinical Microbiology, Zealand University Hospital, Koege, Denmark.
| | - Michael Kemp
- The Regional Department of Clinical Microbiology, Zealand University Hospital, Koege, Denmark
| | - Christen R Stensvold
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institute, Copenhagen, Denmark
| | - Henrik V Nielsen
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institute, Copenhagen, Denmark
| | | | - Anders Porskrog
- Department of Infectious Diseases, Zealand University Hospital, Roskilde, Denmark
| | - Ram B Dessau
- The Regional Department of Clinical Microbiology, Zealand University Hospital, Koege, Denmark
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2
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Hartmeyer GN, Stensvold CR, Fabricius T, Marmolin ES, Hoegh SV, Nielsen HV, Kemp M, Vestergaard LS. Plasmodium cynomolgi as Cause of Malaria in Tourist to Southeast Asia, 2018. Emerg Infect Dis 2020; 25:1936-1939. [PMID: 31538931 PMCID: PMC6759256 DOI: 10.3201/eid2510.190448] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We report human infection with simian Plasmodium cynomolgi in a tourist from Denmark who had visited forested areas in peninsular Malaysia and Thailand in August and September 2018. Because P. cynomolgi may go unnoticed by standard malaria diagnostics, this malaria species may be more common in humans than was previously thought.
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Paulos S, Köster PC, de Lucio A, Hernández-de-Mingo M, Cardona GA, Fernández-Crespo JC, Stensvold CR, Carmena D. Occurrence and subtype distribution of Blastocystis
sp. in humans, dogs and cats sharing household in northern Spain and assessment of zoonotic transmission risk. Zoonoses Public Health 2018; 65:993-1002. [DOI: 10.1111/zph.12522] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 08/07/2018] [Accepted: 08/09/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Silvia Paulos
- Microbiology Service; Quirón Madrid University Hospital; Madrid Spain
| | - Pamela C. Köster
- Parasitology Reference and Research Laboratory; National Centre for Microbiology, Carlos III Health Institute; Madrid Spain
| | - Aida de Lucio
- Parasitology Reference and Research Laboratory; National Centre for Microbiology, Carlos III Health Institute; Madrid Spain
| | - Marta Hernández-de-Mingo
- Parasitology Reference and Research Laboratory; National Centre for Microbiology, Carlos III Health Institute; Madrid Spain
| | | | - Juan C. Fernández-Crespo
- Sub-Direction of Public Health of Álava, Department of Health; Basque Government; Vitoria-Gasteiz Spain
| | - Christen R. Stensvold
- Department of Bacteria, Parasites and Fungi; Statens Serum Institut; Copenhagen Denmark
| | - David Carmena
- Parasitology Reference and Research Laboratory; National Centre for Microbiology, Carlos III Health Institute; Madrid Spain
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Cacciò SM, Sannella AR, Bruno A, Stensvold CR, David EB, Guimarães S, Manuali E, Magistrali C, Mahdad K, Beaman M, Maserati R, Tosini F, Pozio E. Multilocus sequence typing of Dientamoeba fragilis identified a major clone with widespread geographical distribution. Int J Parasitol 2016; 46:793-798. [DOI: 10.1016/j.ijpara.2016.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/07/2016] [Accepted: 07/08/2016] [Indexed: 11/30/2022]
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Hebbelstrup Jensen B, Stensvold CR, Struve C, Olsen KEP, Scheutz F, Boisen N, Röser D, Andreassen BU, Nielsen HV, Schønning K, Petersen AM, Krogfelt KA. Enteroaggregative Escherichia coli in Daycare-A 1-Year Dynamic Cohort Study. Front Cell Infect Microbiol 2016; 6:75. [PMID: 27468409 PMCID: PMC4942469 DOI: 10.3389/fcimb.2016.00075] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 06/29/2016] [Indexed: 12/24/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) has been associated with persistent diarrhea, reduced growth acceleration, and failure to thrive in children living in developing countries and with childhood diarrhea in general in industrialized countries. The clinical implications of an EAEC carrier-status in children in industrialized countries warrants clarification. To investigate the pathological significance of an EAEC carrier-state in the industrialized countries, we designed a 1-year dynamic cohort study and performed follow-up every second month, where the study participants submitted a stool sample and answered a questionnaire regarding gastrointestinal symptoms and exposures. Exposures included foreign travel, consumption of antibiotics, and contact with a diseased animal. In the capital area of Denmark, a total of 179 children aged 0–6 years were followed in a cohort study, in the period between 2009 and 2013. This is the first investigation of the incidence and pathological significance of EAEC in Danish children attending daycare facilities. Conventional microbiological detection of enteric pathogens was performed at Statens Serum Institute, Copenhagen, Denmark, and at Hvidovre Hospital, Copenhagen, Denmark. Parents completed questionnaires regarding gastrointestinal symptoms. The EAEC strains were further characterized by serotyping, phylogenetic analysis, and susceptibility testing. EAEC was detected in 25 (14%) of the children during the observational period of 1 year. One or more gastrointestinal symptoms were reported from 56% of the EAEC-positive children. Diarrhea was reported in six (24%) of the EAEC positive children, but no cases of weight loss, and general failure to thrive were observed. The EAEC strains detected comprised a large number of different serotypes, confirming the genetic heterogeneity of this pathotype. EAEC was highly prevalent (n = 25, 14%) in Danish children in daycare centers and was accompanied by gastrointestinal symptoms in 56% of the infected children. No serotype or phylogenetic group was specifically linked to children with disease.
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Affiliation(s)
| | - Christen R Stensvold
- Department of Microbiology and Infection Control, Statens Serum Institute Copenhagen, Denmark
| | - Carsten Struve
- Department of Microbiology and Infection Control, Statens Serum Institute Copenhagen, Denmark
| | - Katharina E P Olsen
- Department of Microbiology and Infection Control, Statens Serum Institute Copenhagen, Denmark
| | - Flemming Scheutz
- Department of Microbiology and Infection Control, Statens Serum Institute Copenhagen, Denmark
| | - Nadia Boisen
- Department of Microbiology and Infection Control, Statens Serum Institute Copenhagen, Denmark
| | - Dennis Röser
- Department of Microbiology and Infection Control, Statens Serum InstituteCopenhagen, Denmark; Department of Pediatrics, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | - Bente U Andreassen
- Department of Pediatrics, H.C. Andersen's Hospital, University of Odense Odense, Denmark
| | - Henrik V Nielsen
- Department of Microbiology and Infection Control, Statens Serum Institute Copenhagen, Denmark
| | - Kristian Schønning
- Department of Clinical Microbiology, Copenhagen University Hospital Hvidovre Copenhagen, Denmark
| | - Andreas M Petersen
- Department of Microbiology and Infection Control, Statens Serum InstituteCopenhagen, Denmark; Department of Clinical Microbiology, Copenhagen University Hospital HvidovreCopenhagen, Denmark; Department of Gastroenterology, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | - Karen A Krogfelt
- Department of Microbiology and Infection Control, Statens Serum Institute Copenhagen, Denmark
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O'Brien Andersen L, Karim AB, Roager HM, Vigsnæs LK, Krogfelt KA, Licht TR, Stensvold CR. Associations between common intestinal parasites and bacteria in humans as revealed by qPCR. Eur J Clin Microbiol Infect Dis 2016; 35:1427-31. [PMID: 27230509 DOI: 10.1007/s10096-016-2680-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 05/13/2016] [Indexed: 02/05/2023]
Abstract
Several studies have shown associations between groups of intestinal bacterial or specific ratios between bacterial groups and various disease traits. Meanwhile, little is known about interactions and associations between eukaryotic and prokaryotic microorganisms in the human gut. In this work, we set out to investigate potential associations between common single-celled parasites such as Blastocystis spp. and Dientamoeba fragilis and intestinal bacteria. Stool DNA from patients with intestinal symptoms were selected based on being Blastocystis spp.-positive (B+)/negative (B-) and D. fragilis-positive (D+)/negative (D-), and split into four groups of 21 samples (B+ D+, B+ D-, B- D+, and B- D-). Quantitative PCR targeting the six bacterial taxa Bacteroides, Prevotella, the butyrate-producing clostridial clusters IV and XIVa, the mucin-degrading Akkermansia muciniphila, and the indigenous group of Bifidobacterium was subsequently performed, and the relative abundance of these bacteria across the four groups was compared. The relative abundance of Bacteroides in B- D- samples was significantly higher compared with B+ D- and B+ D+ samples (P < 0.05 and P < 0.01, respectively), and this association was even more significant when comparing all parasite-positive samples with parasite-negative samples (P < 0.001). Additionally, our data revealed that a low abundance of Prevotella and a higher abundance of Clostridial cluster XIVa was associated with parasite-negative samples (P < 0.05 and P < 0.01, respectively). Our data support the theory that Blastocystis alone or combined with D. fragilis is associated with gut microbiota characterized by low relative abundances of Bacteroides and Clostridial cluster XIVa and high levels of Prevotella.
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Affiliation(s)
- L O'Brien Andersen
- Unit of Mycology and Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300, Copenhagen S, Denmark
| | - A B Karim
- Unit of Mycology and Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300, Copenhagen S, Denmark
| | - H M Roager
- National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - L K Vigsnæs
- National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - K A Krogfelt
- Unit of Mycology and Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300, Copenhagen S, Denmark
| | - T R Licht
- National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - C R Stensvold
- Unit of Mycology and Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300, Copenhagen S, Denmark.
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Poulsen CS, Efunshile AM, Nelson JA, Stensvold CR. Epidemiological Aspects of Blastocystis Colonization in Children in Ilero, Nigeria. Am J Trop Med Hyg 2016; 95:175-9. [PMID: 27139454 DOI: 10.4269/ajtmh.16-0074] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/28/2016] [Indexed: 11/07/2022] Open
Abstract
This study aimed to elucidate aspects of the epidemiology of Blastocystis in Nigerian school children, including the distribution of subtypes (STs) and ST alleles. A total of 199 genomic DNAs extracted from fecal samples from 199 Nigerian children aged 2-14 years were tested by real-time polymerase chain reaction for Blastocystis Positive DNAs were submitted to barcoding by PCR and sequencing to obtain information on STs and ST alleles. A total of 167 (84%) samples were positive for Blastocystis, with prevalence increasing by age. No association between Blastocystis colonization and gender (P = 0.51) or type/presence of toilet facilities (P = 0.21) was observed. Blastocystis carriers were more prone to using water collected from wells than from sachets (P = 0.0044). Moreover, Blastocystis positivity was associated with positivity for fecal-orally transmitted protozoa (P = 0.018) and helminths (P < 0.0001). A clear inverse association of Blastocystis colonization and malaria infection was observed (P < 0.0001); however, malaria-positive children being younger than malaria-negative children, this finding was attributed to the age effect of Blastocystis colonization. ST data were available for 127/167 (76%) samples. Fifty-one children were positive for ST1, while 42 and 33 children were colonized with ST2 and ST3, respectively; a single case of ST7 was observed. By and large, the ST alleles identified for ST1 and ST2 did not differ from those observed in humans in other regions of the world; meanwhile, the distribution of ST3 alleles was remarkably distinct and potentially specific to humans in sub-Saharan Africa.
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Affiliation(s)
- Casper S Poulsen
- Laboratory of Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Akinwale M Efunshile
- Institute of Medical Microbiology and Infectious Disease Epidemiology, Faculty of Medicine, University of Leipzig, Leipzig, Germany. Department of Medical Microbiology, Ebonyi State University, Abakaliki, Nigeria
| | - Jenna A Nelson
- Department of Public Health Studies, Elon University, Elon, North Carolina
| | - Christen R Stensvold
- Laboratory of Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
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Bremer Christensen C, Soelberg J, Stensvold CR, Jäger AK. Activity of medicinal plants from Ghana against the parasitic gut protist Blastocystis. J Ethnopharmacol 2015; 174:569-575. [PMID: 25773490 DOI: 10.1016/j.jep.2015.03.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 03/01/2015] [Accepted: 03/03/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The plants tested in this study were examples of plants historically used to treat or alleviate several types of stomach disorders manifested by e.g. stomachache, diarrhoea or dysentery. These plants have been consumed typically as a decoction, sometimes mixed with other flavourings. The aim of this study was to evaluate the anti-Blastocystis activity of 24 plant parts from 21 medicinal plants from Ghana. MATERIALS AND METHODS The medicinal plants were collected in the Greater Accra region of Ghana. Every plant part was tested in three different extracts; an ethanolic, a warm, and a cold water extract, at a final concentration of 1 mg/mL for the initial screening, and in a range from 0.0156 to 1mg/mL for determination of inhibitory concentrations. The obligate anaerobic parasitic gut protist Blastocystis (subtype 4) was used as a 48 h old subcultivated isolate in the final concentration of 10(6) cells/mL. Plant extracts inoculated with Blastocystis were incubated at 37 °C for 24 h and 48 h. Both MIC minimum inhibitory concentration (MIC90) assays and minimal lethal concentration (MLC) assays were performed after 24 h and 48 h. The half maximal inhibitory concentration (IC50) was derived after 24 h and 48 h. Antimicrobial activity was tested against two Gram-positive and two Gram-negative bacteria for all 24 plant parts at a final concentration of 1mg/mL. RESULTS Screening of the 24 different plant parts showed significant anti-Blastocystis activity of six of the ethanolic extracts: Mallotus oppositifolius, IC50, 24 h 27.8 µg/mL; Vemonia colorata, IC50, 24 h 117.9 µg/mL; Zanthoxylum zanthoxyloides, cortex IC50, 24 h 255.6 µg/mL; Clausena anisata, IC50, 24 h 314.0 µg/mL; Z. zanthoxyloides, radix IC50, 24 h 335.7 µg/mL and Eythrina senegalensis, IC50, 24 h 527.6 µg/mL. The reference anti-protozoal agent metronidazole (MTZ) had an IC50, 24 h of 7.6 µg/mL. Only C. anisata showed antimicrobial activity at a concentration of 800 µg/mL. CONCLUSION Six ethanolic plant extracts showed significant anti-parasitic activity against Blastocystis. M. oppositifolius showed nearly as good activity as the reference anti-protozoal drug MTZ. Historically, the active plants found in this study have been used against dysentery, diarrhoea or other stomach disorders. Nowadays they are not used specifically for dysentery, but they are being used as medicinal plants against various stomach disorders.
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Affiliation(s)
- Charlotte Bremer Christensen
- Department of Drug Design and Pharmacology, Universitetsparken 2, DK-2100 Copenhagen, Denmark; Laboratory of Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark
| | - Jens Soelberg
- Department of Drug Design and Pharmacology, Universitetsparken 2, DK-2100 Copenhagen, Denmark; Museum of Natural Medicine, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Christen R Stensvold
- Laboratory of Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark
| | - Anna K Jäger
- Department of Drug Design and Pharmacology, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
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Efunshile MA, Ngwu BAF, Kurtzhals JAL, Sahar S, König B, Stensvold CR. Molecular Detection of the Carriage Rate of Four Intestinal Protozoa with Real-Time Polymerase Chain Reaction: Possible Overdiagnosis of Entamoeba histolytica in Nigeria. Am J Trop Med Hyg 2015; 93:257-62. [PMID: 26101274 DOI: 10.4269/ajtmh.14-0781] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 04/11/2015] [Indexed: 12/17/2022] Open
Abstract
Diarrhea remains the second largest killer of children worldwide, and Nigeria ranks number two on the list of global deaths attributable to diarrhea. Meanwhile, prevalence studies on potentially diarrheagenic protozoa in asymptomatic carriers using molecular detection methods remain scarce in sub-Saharan countries. To overcome sensitivity issues related to microscopic detection and identification of cysts in stool concentrates, real-time polymerase chain reaction (PCR) was used to analyze genomic DNAs extracted from stool samples from 199 healthy school children for Entamoeba histolytica, E. dispar, Giardia intestinalis, and Cryptosporidium. Questionnaires were administered for epidemiological data collection. E. histolytica was not detected in any of the samples, whereas Giardia (37.2%), E. dispar (18.6%), and Cryptosporidium (1%) were found. Most of the children sourced their drinking water from community wells (91%), while the majority disposed of feces in the bush (81.9%). Our study is the first to use real-time PCR to evaluate the epidemiology of E. histolytica, Giardia, and Cryptosporidium in Nigeria where previous studies using traditional diagnostic techniques have suggested higher and lower carriage rates of E. histolytica and Giardia, respectively. It is also the first study to accurately identify the prevalence of common potentially diarrheagenic protozoa in asymptomatic carriers in sub-Saharan Africa.
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Affiliation(s)
- Michael A Efunshile
- Institute of Medical Microbiology and Infectious Disease Epidemiology, Medical Faculty, University of Leipzig, Leipzig, Germany; Ebonyi State University, Abakaliki, Nigeria; Department of Clinical Microbiology, Centre for Medical Parasitology, Copenhagen University Hospital Copenhagen, Denmark; Department of International Health, Immunology, and Microbiology, University of Copenhagen, Denmark; Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Bethrand A F Ngwu
- Institute of Medical Microbiology and Infectious Disease Epidemiology, Medical Faculty, University of Leipzig, Leipzig, Germany; Ebonyi State University, Abakaliki, Nigeria; Department of Clinical Microbiology, Centre for Medical Parasitology, Copenhagen University Hospital Copenhagen, Denmark; Department of International Health, Immunology, and Microbiology, University of Copenhagen, Denmark; Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Jørgen A L Kurtzhals
- Institute of Medical Microbiology and Infectious Disease Epidemiology, Medical Faculty, University of Leipzig, Leipzig, Germany; Ebonyi State University, Abakaliki, Nigeria; Department of Clinical Microbiology, Centre for Medical Parasitology, Copenhagen University Hospital Copenhagen, Denmark; Department of International Health, Immunology, and Microbiology, University of Copenhagen, Denmark; Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Sumrin Sahar
- Institute of Medical Microbiology and Infectious Disease Epidemiology, Medical Faculty, University of Leipzig, Leipzig, Germany; Ebonyi State University, Abakaliki, Nigeria; Department of Clinical Microbiology, Centre for Medical Parasitology, Copenhagen University Hospital Copenhagen, Denmark; Department of International Health, Immunology, and Microbiology, University of Copenhagen, Denmark; Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Brigitte König
- Institute of Medical Microbiology and Infectious Disease Epidemiology, Medical Faculty, University of Leipzig, Leipzig, Germany; Ebonyi State University, Abakaliki, Nigeria; Department of Clinical Microbiology, Centre for Medical Parasitology, Copenhagen University Hospital Copenhagen, Denmark; Department of International Health, Immunology, and Microbiology, University of Copenhagen, Denmark; Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Christen R Stensvold
- Institute of Medical Microbiology and Infectious Disease Epidemiology, Medical Faculty, University of Leipzig, Leipzig, Germany; Ebonyi State University, Abakaliki, Nigeria; Department of Clinical Microbiology, Centre for Medical Parasitology, Copenhagen University Hospital Copenhagen, Denmark; Department of International Health, Immunology, and Microbiology, University of Copenhagen, Denmark; Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
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Scanlan PD, Stensvold CR, Rajilić-Stojanović M, Heilig HGHJ, De Vos WM, O'Toole PW, Cotter PD. The microbial eukaryote Blastocystis is a prevalent and diverse member of the healthy human gut microbiota. FEMS Microbiol Ecol 2014; 90:326-30. [PMID: 25077936 DOI: 10.1111/1574-6941.12396] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/22/2014] [Accepted: 07/24/2014] [Indexed: 12/18/2022] Open
Abstract
To date, the majority of research into the human gut microbiota has focused on the bacterial fraction of the community. Inevitably, this has resulted in a poor understanding of the diversity and functionality of other intestinal microorganisms in the human gut. One such nonbacterial member is the microbial eukaryote Blastocystis, which has been implicated in the aetiology of a range of different intestinal and extra-intestinal diseases. However, prevalence data from different studies are conflicting, and crucially, there is limited information on its incidence and diversity in healthy individuals. Here, we survey the prevalence, genetic diversity and temporal stability of Blastocystis in a group of healthy adults (n = 105) using a sensitive PCR assay. Blastocystis was present in 56% of our sample set, which is much higher than previously reported from an industrialised county (Ireland). Moreover, a diversity of different subtypes (species) were detected, and Blastocystis was present in a subset of individuals sampled over a period of time between 6 and 10 years, indicating that it is capable of long-term host colonisation. These results show that Blastocystis is a common and diverse member of the healthy gut microbiota, thereby extending our knowledge of the microbial ecology of the healthy human intestine.
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11
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Monroy-Vaca EX, de Armas Y, Illnait-Zaragozí MT, Diaz R, Toraño G, Vega D, Álvarez-Lam I, Calderón EJ, Stensvold CR. Genetic diversity of Pneumocystis jirovecii in colonized Cuban infants and toddlers. Infection, Genetics and Evolution 2014; 22:60-6. [DOI: 10.1016/j.meegid.2013.12.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/10/2013] [Accepted: 12/29/2013] [Indexed: 11/16/2022]
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12
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Scanlan PD, Stensvold CR. Blastocystis: getting to grips with our guileful guest. Trends Parasitol 2013; 29:523-9. [PMID: 24080063 DOI: 10.1016/j.pt.2013.08.006] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 08/30/2013] [Accepted: 08/30/2013] [Indexed: 12/22/2022]
Abstract
Blastocystis, a common single-celled intestinal parasite of humans and animals, continues to puzzle clinical microbiologists, gastroenterologists, and general practitioners who are still unsure of the clinical significance of the organism. Here we consider some less well-addressed areas of Blastocystis research, which, facilitated by recent technological advances, could potentially turn out to be significant pathways to knowledge. First and foremost we discuss new trends in Blastocystis research, including the 'omics' perspectives, and then highlight some aspects of Blastocystis research in the context of host coevolution, its potential as a biomarker of intestinal functionality, and its relationship to other components of the human intestinal microbiota.
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Affiliation(s)
- Pauline D Scanlan
- Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork, Cork, Ireland.
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13
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Nagel R, Cuttell L, Stensvold CR, Mills PC, Bielefeldt-Ohmann H, Traub RJ. Blastocystis subtypes in symptomatic and asymptomatic family members and pets and response to therapy. Intern Med J 2013; 42:1187-95. [PMID: 22032439 DOI: 10.1111/j.1445-5994.2011.02626.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 07/31/2011] [Indexed: 12/13/2022]
Abstract
BACKGROUND Blastocystis is a common, enteric parasite. The pathogenicity of the organism is uncertain, but subtypes (ST) 1 and 3 have been reported more likely to cause irritable bowel-like symptoms. AIMS We treated symptomatic patients positive for Blastocystis with conventional therapy and analysed 16 small-subunit (SSU) rDNA to assess clearance and carriage rates and ST prevalence of the parasite in the asymptomatic household members. METHODS In a longitudinal, prospective case study, 11 symptomatic patients positive for Blastocystis underwent outpatient clinical assessment to exclude other diagnoses before 14 days of either metronidazole 400 mg three times daily or trimethoprim/sulfamethoxazole 160/800 mg twice-daily therapy. Faecal specimens were collected from patients at baseline, day 15, 28 and 56 after therapy and from 17 family members and eight pets at day 15. Specimens were analysed using faecal smear, culture and polymerase chain reaction analysis of 16SSU rDNA. RESULTS No patient cleared the organism following therapy. ST 1 (45%), 3 (36%), 4 (36%) and 6 (9%) were found in the symptomatic Blastocystis patients, and ST identified before and after therapy were identical in each individual. All household contacts were positive for Blastocystis and 16/17 (94%) contacts showed identical Blastocystis ST to the symptomatic family member. All pets were positive for Blastocystis with polymerase chain reaction testing, 7/8 (88%) demonstrating ST concordance with the symptomatic Blastocystis patients. CONCLUSIONS Conventional therapy is ineffective for symptomatic Blastocystis infection. The high prevalence of Blastocystis infection within households suggested transmission between humans and their pets. Subtyping analysis of SSU rDNA alone in Blastocystis does not appear to predict pathogenicity.
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Affiliation(s)
- R Nagel
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
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14
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Zhao Y, Stensvold CR, Perlin DS, Arendrup MC. Azole resistance in Aspergillus fumigatus from bronchoalveolar lavage fluid samples of patients with chronic diseases. J Antimicrob Chemother 2013; 68:1497-504. [PMID: 23463213 DOI: 10.1093/jac/dkt071] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Triazole resistance in Aspergillus fumigatus has been increasing. We explored the A. fumigatus azole resistance profiles in bronchoalveolar lavage (BAL) fluid samples from Danish patients examined for aspergillosis. METHODS A total of 94 BAL samples from 87 patients were evaluated by galactomannan (GM) test and A. fumigatus CYP51A profiling by PCR. RESULTS Aspergillus spp. were isolated from 27/48 (56.3%) cultured samples, including 23 A. fumigatus with one resistant strain (4.3%). Samples were classified into GM-positive (≥3.0), GM-intermediate (0.5 to <3.0) and GM-negative (<0.5) groups, where the CYP51A PCR was positive in 81.8% (36/44), 56.3% (18/32) and 38.9% (7/18) of samples, respectively. Nine CYP51A PCR-positive samples (9/61, 14.8%) were found to have mutations resulting in amino acid substitutions. M220V was detected from a sample culture positive for susceptible A. fumigatus and P216L was found in a culture-negative BAL sample. Conversely, no mutation was found in one sample culture positive for azole-resistant A. fumigatus. The tandem repeat/L98H mutation was not detected. CONCLUSIONS Our study shows that azole resistance in A. fumigatus can be cryptic and may go undiagnosed. The combination of improved culture/susceptibility tests and the direct molecular detection of resistance markers will facilitate prompt institution of appropriate antifungal therapy.
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Affiliation(s)
- Yanan Zhao
- Public Health Research Institute Center, UMDNJ-NJMS, Newark, NJ 07103, USA
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15
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Nourmoradi H, Nikaeen M, Stensvold CR, Mirhendi H. Ultraviolet irradiation: An effective inactivation method of Aspergillus spp. in water for the control of waterborne nosocomial aspergillosis. Water Res 2012; 46:5935-5940. [PMID: 22985523 DOI: 10.1016/j.watres.2012.08.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 05/31/2012] [Accepted: 08/11/2012] [Indexed: 06/01/2023]
Abstract
Invasive aspergillosis is the second most common cause of nosocomial fungal infections and occurring mainly by Aspergillus fumigatus, Aspergillus flavus, and Aspergillus niger. There is evidence that nosocomial aspergillosis may be waterborne. This study was conducted to evaluate the ultraviolet (UV) irradiation efficiency in terms of inactivating the most important Aspergillus species in water since these are potential sources for nosocomial aspergillosis. A continuous flow UV reactor which could be used as a point-of-use (POU) system was used to survey Aspergillus inactivation by UV irradiation. The inactivation efficiency of UV fluence (4.15-25 mJ/cm(2)) was measured by determination of fungal density in water before and after radiation. Because turbidity and iron concentration are two major water quality factors impacting UV disinfection effectiveness, the potential influence of these factors on UV inactivation of Aspergillus spp. was also measured. The 4 log inactivation for A. fumigatus, A. niger and A. flavus at a density of 1000 cfu/ml was achieved at UV fluences of 12.45 mJ/cm(2), 16.6 mJ/cm(2) and 20.75 mJ/cm(2), respectively. The inactivation efficiency for lower density (100 cfu/ml) was the same as for the higher density except for A. flavus. The removal efficiency of Aspergillus spp. was decreased by increasing the turbidity and iron concentration. UV disinfection could effectively inactivate Aspergillus spores from water and eliminate potential exposure of high-risk patients to fungal aerosols by installation of POU UV systems.
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Affiliation(s)
- H Nourmoradi
- Department of Environmental Health Engineering, School of Health, Ilam University of Medical Sciences, Ilam, Iran
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16
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Rene BA, Stensvold CR, Badsberg JH, Nielsen HV. Subtype analysis of Blastocystis isolates from Blastocystis cyst excreting patients. Am J Trop Med Hyg 2009; 80:588-592. [PMID: 19346381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
To determine the distribution of Blastocystis sp. subtypes from Blastocystis cyst excreters, 1,000 fecal samples from patients suspected of enteroparasitic disease were scored for stool consistency, submitted to xenic in vitro culture (XIVC), formol ethyl acetate concentration (FECT) with subsequent isopycnic centrifugation, and polymerase chain reaction (PCR) with subtype (ST) analysis. Blastocystis was significantly more prevalent in specimens from patients with travel-associated diarrhea (15.6%) than those with persistent diarrhea (8.3%) (P = 0.005). Overall, 115 (11.5%) and 35 (3.5%) specimens were positive by XIVC and FECT, respectively. Blastocystis cysts were detected in 33 (28.7%) of the XIVC-positive specimens. A positive FECT result was associated with ST3 (P = 0.05). The presence of Blastocystis in general or Blastocystis cysts was independent of stool consistency, and no particular ST was significantly associated with cyst identification. In view of these data, the present study indicates that Blastocystis cyst formation is independent of Blastocystis sp. subtype and gastrointestinal transit time.
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Affiliation(s)
- Betangbeh A Rene
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Copenhagen, Denmark
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17
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Rene BA, Nielsen HV, Stensvold CR, Badsberg JH. Subtype Analysis of Blastocystis Isolates from Blastocystis Cyst Excreting Patients. Am J Trop Med Hyg 2009. [DOI: 10.4269/ajtmh.2009.80.588] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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18
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Stensvold CR, Arendrup MC, Nielsen HV, Bada A, Thorsen S. Symptomatic infection with Blastocystis sp. subtype 8 successfully treated with trimethoprim-sulfamethoxazole. Ann Trop Med Parasitol 2008; 102:271-4. [PMID: 18348782 DOI: 10.1179/136485908x278847] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- C R Stensvold
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
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19
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Abstract
A 59-year-old Danish woman presented to her general practitioner (GP) at the end of June. A few weeks earlier, during a meal at home in Denmark, she had consumed a slice of pork sausage (‘teewurst’, German sausage) brought to her by three Polish visitors.
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Affiliation(s)
- C R Stensvold
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Copenhagen, Denmark.
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20
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Stensvold CR, Arendrup MC, Mølbak K, Nielsen HV. The prevalence of Dientamoeba fragilis in patients with suspected enteroparasitic disease in a metropolitan area in Denmark. Clin Microbiol Infect 2007; 13:839-42. [PMID: 17610603 DOI: 10.1111/j.1469-0691.2007.01760.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The prevalence of Dientamoeba fragilis in patients from a metropolitan area in Denmark was determined by examination of paired stool samples using two techniques: a formol ethyl-acetate concentration technique with unpreserved faeces and a permanent staining technique on faeces preserved with sodium acetate-acetic acid-formalin (SAF). Using the SAF permanent staining technique and the formol ethyl-acetate concentration technique, 25% and 15% of the specimens, respectively, were parasite-positive. D. fragilis was detected in 12 of the 103 patients, only two of whom harboured other recognised pathogenic parasites. Overall, D. fragilis had a remarkably high prevalence in the metropolitan area of Denmark investigated.
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Affiliation(s)
- C R Stensvold
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institute, Copenhagen, Denmark.
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21
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Stensvold CR, Traub RJ, von Samson-Himmelstjerna G, Jespersgaard C, Nielsen HV, Thompson RCA. Blastocystis: subtyping isolates using pyrosequencing technology. Exp Parasitol 2006; 116:111-9. [PMID: 17266951 DOI: 10.1016/j.exppara.2006.12.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 12/01/2006] [Accepted: 12/08/2006] [Indexed: 10/23/2022]
Abstract
Blastocystis is a prevalent single-celled enteric parasite of unresolved clinical significance. Efforts based on molecular methodologies to establish whether pathogenicity is linked to specific isolates of the genetically diverse genus of Blastocystis have been scarce and so far yielded ambiguous results which can be difficult to interpret. To alleviate some of the problems related to unravelling the molecular epidemiology of Blastocystis infections we developed and evaluated a simple and high-throughput sequence analysis (SQA) pyrosequencing technique based on the detection of genotype-specific nucleotide polymorphisms in the 18S small subunit rRNA gene for a rapid and cost-effective post-PCR screening of Blastocystis genotypes. The method was effectively capable of genotyping 48/48 isolates positive by nested PCR in approximately one hour, and in 94% of the cases the isolate detected by PCR and pyrosequencing was also detected by one of two different PCR assays with subsequent dideoxy sequencing.
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Affiliation(s)
- C R Stensvold
- Laboratory of Parasitology, Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
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22
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Stensvold CR, Saijuntha W, Sithithaworn P, Wongratanacheewin S, Strandgaard H, Ornbjerg N, Johansen MV. Evaluation of PCR based coprodiagnosis of human opisthorchiasis. Acta Trop 2006; 97:26-30. [PMID: 16253202 DOI: 10.1016/j.actatropica.2005.08.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 05/01/2005] [Accepted: 08/02/2005] [Indexed: 01/23/2023]
Abstract
In this study, a recently developed PCR test for the detection of Opisthorchis viverrini in human faecal samples was evaluated using two parasitological methods as references. During a survey of foodborne trematodes (FBT) in the Vientiane Province, Lao PDR, 85 samples were collected and evaluated for FBT eggs by the Kato Katz (KK) technique, the formalin ethyl acetate concentration technique (FECT) and a PCR analysis for the distinction between O. viverrini and other FBT. The two parasitological methods did not differ in the ability of detecting FBT eggs, and a single KK reading was characterized by a sensitivity of 85% when compared to two FECT readings. The PCR tested positive only in cases where eggs had been demonstrated by parasitological examination. However, the PCR tested negative in some samples with very high egg counts. Demonstrating a PCR sensitivity of approximately 50% in samples with faecal egg counts>1000, the previously reported PCR sensitivity based on in vitro studies was not supported. It is believed that technical problems rather than diagnostic reference related issues were responsible for the relatively low PCR performance. Further studies should aim at optimizing DNA extraction and amplification, and future PCR evaluation should include specificity control such as the scanning electron microscopy of eggs in test samples or the expulsion of adult trematodes from PCR tested individuals.
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Affiliation(s)
- C R Stensvold
- Danish Bilharziasis Laboratory (DBL), Institute for Health Research and Development, Jaergersborg Allé 1D, DK-2920 Charlottenlund, Denmark
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